The pressure to use biodegradable disposable packaging has been steadily increasing in the last decade. As recently as March, 2003, Taiwan has outlawed the use of Styrofoam in disposable packaging. Even China's major cities such as Beijing and Shanghai have outlawed the use of Styrofoam materials in disposable packaging. Various attempts have been made in the prior art to manufacture starch based disposables for use in food service items such as trays, plates, and bowls. Some methods include producing starch based packaging that has materials vented in excess of the final product as can be evidenced when one inspects the finished product. However, these technologies use male and female molds and not extrusion dies. Attempts to extrude starch do not include venting during the extrusion process, and instead include injection gases in an attempt to foam the starch.
Further, the majority of the existing extrusion processes using starch are geared towards producing thick sheeted materials that are then bonded together to form packaging materials that replace thick Styrofoam. Examples are protective packaging for shipping television sets or other similar electronic or heavy systems. Unfortunately, existing efforts have not been successful for producing articles such as toilet paper rolls, chop sticks, or straws primarily due to the inability to reduce pressures during the baking-extrusion process.
Accordingly, there is a need for improved systems and methods for extruding materials while continually venting gases during the extrusion process without any substantial material losses.